Lymphedema: Pathogenesis and Novel Therapies

Potential therapeutic effect of a ketogenic diet for the treatment of lymphoedema: Results of an exploratory study

BACKGROUND

Lymphoedema is a chronic and progressive disease characterised by excessive accumulation of lymph in the interstitial compartment, leading to tissue swelling and fibroadipose deposition. Lymphangiogenesis is partly regulated by ketone body oxidation, and a ketogenic diet (KD) has shown therapeutic efficacy in a preclinical mouse tail lymphoedema model. Therefore, we aimed to investigate the potential therapeutic effect of a KD in patients with secondary lymphoedema.

METHODS

Nine patients with unilateral stage 2 lymphoedema secondary to lymphadenectomy were included in this quasi-experimental exploratory study consisting of a short run-in phase to gradually induce ketosis, followed by a classic KD (CKD) and modified Atkins diet (MAD) phase during which patients consumed a CKD and MAD, respectively. Lymphatic function and oedema volume, the primary outcomes, were assessed at baseline and at the end of both the CKD and MAD phase. Secondary outcomes included health-related and lymphedema-specific quality of life (QoL).

RESULTS

Seven out of nine patients completed the study protocol. Lymphatic function was improved upon consumption of both a CKD (dermal backflow score [mean ± SD]: 7.29 ± 2.98 vs. 10.86 ± 2.19 at baseline; p = 0.03) and MAD (6.71 ± 2.06; p = 0.02), whereas oedema volume did not decrease during the course of the study (excess limb volume [mean ± SD]: 20.13 ± 10.25% at end of CKD and 24.07 ± 17.77% at end of MAD vs. 20.79 ± 12.96% at baseline; p > 0.99 and p > 0.30, respectively). No changes were observed in health-related, nor lymphoedema-specific QoL at the end of CKD and MAD.

CONCLUSIONS

The consumption of a KD improved lymphatic function and was associated with a clinically meaningful reduction in oedema volume in some patients (3/7 at end of CKD, 2/7 at end of MAD) with unilateral stage 2 secondary lymphoedema. These results highlight the potential of a KD to improve lymphatic function in patients with lymphoedema. However, further studies are required to substantiate our findings.

Personalizing Locoregional Therapy in Patients With Breast Cancer in 2024: Tailoring Axillary Surgery, Escalating Lymphatic Surgery, and Implementing Evidence-Based Hypofractionated Radiotherapy

The management of axillary lymph nodes in breast cancer is continually evolving. Recent data now support omitting axillary lymph node dissection (ALND) in most patients with metastases in up to two sentinel lymph nodes (SLNs) during upfront surgery and those with residual isolated tumor cells after neoadjuvant chemotherapy (NACT). In the upfront surgery setting, ALND is still indicated, however, in patients with clinically node-positive breast cancer or more than two positive SLNs and, after NACT, in case of residual micrometastases and macrometastases. Omission of the sentinel lymph node biopsy (SLNB) can be considered in many postmenopausal patients with small luminal breast cancer, particularly when axillary ultrasound is negative. Several randomized controlled trials (RCTs) are currently aiming at eliminating the remaining indications for ALND and also establishing omission of SLNB in a broader patient population. The movement to deescalate axillary staging is in part because of the association between ALND and lymphedema, which is swelling of an extremity because of lymphatic damage and obstructed lymphatic drainage. To reduce the risk of developing this condition, patients undergoing ALND can undergo reverse mapping of the axilla and immediate reconstruction or bypass of the lymphatics from the involved extremity. Decongestion and compression are the foundation of conservative treatment for established lymphedema, while lymphovenous bypass and lymph node transfer are surgical procedures to address the physiologic dysfunction. Radiotherapy is an essential component of breast locoregional therapy: more than three decades of radiation research has optimized treatment according to patient's risk of local recurrence while substantially reducing the number of treatment visits. High-quality RCTs have shown the efficacy and safety of hypofractionation-more than 2Gy radiation dose per treatment (fraction)-significantly reducing the burden of radiotherapy treatment for many patients with breast cancer. In 2024, guidelines recommend no more than 15-16 fractions for whole-breast and nodal radiotherapy, with some recommending five fractions for whole-breast radiotherapy. In addition, simultaneous integrated boost (SIB) has been shown to be noninferior to sequential boost with regards to ipsilateral breast tumor recurrence with similar or reduced long-term side effects, also reducing overall treatment length. Further RCTs are underway investigating other indications for five fractions, including SIB and regional node irradiation, such that, in future, it may be possible for the majority of breast radiotherapy patients to be treated with a 1-week course. This manuscript serves to outline the latest updates on axillary surgical staging, lymphatic surgery, and evidence-based radiotherapy in the treatment of breast cancer.

New Strategies for Locally Advanced Breast Cancer: A Review of Inflammatory Breast Cancer and Nonresponders

This review explores the new strategies around the management of locally advanced breast cancer (LABC), particularly for nonresponsive tumors and/or initially unresectable tumors at diagnosis, inclusive of inflammatory breast cancer. Nonresponders to neoadjuvant systemic therapy present a unique clinical challenge. Emerging medical therapeutics as well as considerations for use of radiotherapy and/or surgery in this setting are discussed. Specifically, the use of neoadjuvant radiotherapy for LABC and lymphedema prevention with lymphatic reconstruction following axillary lymph node dissection are reviewed.

Synchronous supraclavicular vascularized lymph node transfer and liposuction for gynecological cancer-related lower extremity lymphedema: a clinical comparative analysis of three different procedures

OBJECTIVE

Gynecological cancer-related lower extremity lymphedema (GC-LEL), a chronic, progressive condition, lacks a standardized treatment. Currently, supraclavicular vascularized lymph node transfer (SC-VLNT) is a favored approach in the treatment of lymphedema, and there is a trend toward combination technology. This study conducts a comparative analysis of three techniques for treating GC-LEL with simultaneous SC-VLNT and liposuction.

METHODS

A cohort of 35 patients with GC-LEL was examined, comprising 13 patients who underwent single lymph nodes flap with a skin paddle (SLNF+P), 12 who received single lymph nodes flap without a skin paddle (SLNF), and 10 who accepted dual lymph nodes flap without a skin paddle (DLNF). Patient demographics and outcomes were meticulously documented, covering intra- and postoperative variables.

RESULTS

The median limb volume reduction were 56.4% (SLNF+P), 60.8% (SLNF), and 50.5% (DLNF) in stage II, and 54.0% (SLNF+P), 59.8% (SLNF), and 54.4% (DLNF) in stage III. DLNF group procedures entailed longer flap harvesting and transplantation times. The SLNF+P group, on average, had an 8-day postoperative hospitalization, longer than others. All patients noted subjective improvements in Lymphedema Quality of Life scores, with lymphoscintigraphy revealing enhanced lymphatic flow in 29 of the 35 cases. A notable decrease in cellulitis incidence was observed. Additionally, the occurrence of cellulitis decreased significantly, except for DLNF (Stage Ⅱ). The median follow-up time was 16 months (range, 12-36 months), with no reported severe postoperative complications.

CONCLUSIONS

For advanced GC-LEL, SLNF combined with liposuction is a preferred treatment, offering fewer complications, shorter operative time, and hospitalization.

Effects of complex decongestive therapy and aquatic physiotherapy on markers of the inflammatory process in individuals with lymphedema

BACKGROUND

Chronic lymphedema is a progressive and inflammatory disease caused by impaired lymphatic transport.

PURPOSE

This study evaluates the effects of complex decongestive therapy (CDT) and aquatic physiotherapy on markers of the inflammatory process and lower limb volumes in individuals with lymphedema.

METHODS

A randomized controlled clinical trial was carried out with three groups: patients with lymphedema submitted to CDT, patients with lymphedema submitted to aquatic physiotherapy, and control group of individuals without lymphedema. The evaluation was performed through blood count, CRP measurements, C3, C4 complement, measurement of serum levels of cytokines interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukins 4 (IL-4), 6 (IL-6), and 10 (IL-10), and the volume of a lower limb using the volume formula of a truncated cone. The study was registered with the Brazilian Clinical Trials Registry (RBR-4tpkszn).

RESULTS

Our work showed a reduction in the TNF-α levels of patients in the CDT group (p = .028). Significant differences were found between the control group and the CDT group for IL-10 (p = .049) and Monocytes (p = .039). No significant reduction in limb volume was found.

CONCLUSION

Our results show that CDT was able to significantly reduce the inflammatory marker TNF-α in patients with lymphedema, suggesting an anti-inflammatory effect of the therapy.

Isolated scrotal lymphedema in a 43-year old male patient: A case report

INTRODUCTION

Lymphedema of the external genitalia is a rare condition characterized by swelling of the scrotal skin and subcutaneous tissue, resulting from a pathology in lymphatic drainage. Over time, the development of fibrosis leads to a considerable impairment in the patient's quality of life. While conservative management is generally the first-line approach, surgical cases may necessitate surgical intervention to achieve comprehensive and lasting improvements.

CASE PRESENTATION

We present the case of a 43-year-old obese male patient who presented to the clinic with a complaint of persistent bilateral scrotal swelling for three months. Clinical examination revealed a pressure-indolent, soft, and massively enlarged swelling of the scrotum on both sides. Ultrasound findings confirmed a diffusely thickened edematous scrotal wall. The patient was advised to start physiotherapy and adhere to conservative management. Due to the debilitating size of the mass, the patient opted for excision of the scrotal swelling followed by scrotoplasty.

CLINICAL DISCUSSION

This case report explores the presentation, signs and symptoms, impact on patients' lives, and various management options for scrotal lymphedema. It underscores the intricacies involved in the diagnosis and treatment decision-making process, emphasizing the need for a tailored and multidisciplinary approach.

CONCLUSION

It is imperative to initially rule out life-threatening causes of scrotal lymphedema to ensure optimal patient care. The integration of surgical interventions should be carefully considered in the overall management strategy for optimal and comprehensive results. Scrotoplasty, in the context of scrotal lymphedema, not only improves the quality of life but also positively influences sexual function.

COMPETENCIES

Interpersonal and communication skills, Medical knowledge, Patient care, Practice-based learning and improvement.

The Role of Inflammation in Lymphedema: A Narrative Review of Pathogenesis and Opportunities for Therapeutic Intervention

Lymphedema is a chronic and progressive disease of the lymphatic system characterized by inflammation, increased adipose deposition, and tissue fibrosis. Despite early hypotheses identifying lymphedema as a disease of mechanical lymphatic disruption alone, the progressive inflammatory nature underlying this condition is now well-established. In this review, we provide an overview of the various inflammatory mechanisms that characterize lymphedema development and progression. These mechanisms contribute to the acute and chronic phases of lymphedema, which manifest clinically as inflammation, fibrosis, and adiposity. Furthermore, we highlight the interplay between current therapeutic modalities and the underlying inflammatory microenvironment, as well as opportunities for future therapeutic development.

Lymphoscintigraphy is frequently recommended but seldom used in a "real world setting"

OBJECTIVE

Lymphedema (LED) lacks a standard, simple, guiding noninvasive diagnostic test, unlike the two other circulatory disorders-arterial or venous disease. Lymphoscintigraphy (LSG) has been recommended by several guidelines as the diagnostic test of choice for LED. Several recent expert panels, however, have suggested from anecdotal experience that LSG was used infrequently, and that the diagnosis of LED is usually based on clinical examination.

METHODS

To determine the use of LSG in a large real-world LED population, the International Business Machines MarketScan Research Database was examined from April 2012 to March 2020 for patients with a new diagnosis of LED (the index date). Use of LSG (LSG+) was ascertained during the period beginning 12 months prior to the initial coding of a LED diagnosis and ending 12 months after the index date based on the corresponding Current Procedural Terminology code; LSG use for sentinel node mapping at the time of oncologic surgery was excluded. Demographic profiles, comorbidities, and causes of LED among patients with and without evidence of LSG were characterized.

RESULTS

We identified 57,674 patients, aged ≥18 years, who had a new diagnosis of LED and health care coverage for ≥12 months before and after this index date. Only a small number (1429; 2.5%) of these patients underwent LSG during the study period. The LSG + cohort was younger (53.7 vs 60.7 years), had a higher proportion of women (91.3% vs 73.4%), but a lower percentage of diabetes (12.8% vs 27.5%), heart failure (2.2% vs 8.7%), hypertension (32.4% vs 51.0%), and obesity (15.1% vs 22.2%) compared with the LED population who did not undergo LSG (all P < .001). Most importantly, the use of LSG for diagnosis varied with the etiology of LED (LSG was most frequently utilized among patients with melanoma-LED (9.5%) and patients with breast cancer-LED (6.7%), in contrast to patients with advanced venous disease-related LED (1.1%; P < .05 for both comparisons).

CONCLUSIONS

Despite four guidelines recommending LSG, including the Guidelines of the American Venous Forum (Handbook of Venous and Lymphatic Disease-4th edition), which recommended LSG "for the initial evaluation of patients with LED" with a 1B recommendation, LSG plays a minor role in establishing the diagnosis of LED in the United States. This underlines the need for a better, simple diagnostic test for LED to complement clinical examination.

Specific Circular RNA Signature of Endothelial Cells: Potential Implications in Vascular Pathophysiology

Circular RNAs (circRNAs) are a recently characterized family of gene transcripts forming a covalently closed loop of single-stranded RNA. The extent of their potential for fine-tuning gene expression is still being discovered. Several studies have implicated certain circular RNAs in pathophysiological processes within vascular endothelial cells and cancer cells independently. However, to date, no comparative study of circular RNA expression in different types of endothelial cells has been performed and analysed through the lens of their central role in vascular physiology and pathology. In this work, we analysed publicly available and original RNA sequencing datasets from arterial, veinous, and lymphatic endothelial cells to identify common and distinct circRNA expression profiles. We identified 4713 distinct circRNAs in the compared endothelial cell types, 95% of which originated from exons. Interestingly, the results show that the expression profile of circular RNAs is much more specific to each cell type than linear RNAs, and therefore appears to be more suitable for distinguishing between them. As a result, we have discovered a specific circRNA signature for each given endothelial cell type. Furthermore, we identified a specific endothelial cell circRNA signature that is composed four circRNAs: circCARD6, circPLXNA2, circCASC15 and circEPHB4. These circular RNAs are produced by genes that are related to endothelial cell migration pathways and cancer progression. More detailed studies of their functions could lead to a better understanding of the mechanisms involved in physiological and pathological (lymph)angiogenesis and might open new ways to tackle tumour spread through the vascular system.

Surgical lymphedema models in the mice hindlimb-A systematic review and quality assessment

BACKGROUND

Lymphedema constitutes a major unsolved problem in plastic surgery. To identify novel lymphedema treatments, preclinical studies are vital. The surgical mouse lymphedema model is popular and cost-effective; nonetheless, a synthesis and overview of the literature with evidence-based guidelines is needed. The aim of this review was to perform a systematic review to establish best practice and support future high-quality animal studies exploring lymphedema treatments.

METHODS

We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searching four databases (PubMed, Embase, Web of Science, and Scopus) from inception-September 2022. The Animals in Research Reporting In Vivo Experiments 2.0 (ARRIVE 2.0) guidelines were used to evaluate reporting quality. Studies claiming to surgically induce lymphedema in the hindlimb of mice were included.

RESULTS

Thirty-seven studies were included. Four main models were used. (1) Irradiation+surgery. (2) A variation of the surgery used by (1) + irradiation. (3) Surgery only (SPDF-model). (4) Surgery only (PLND-model). Remaining studies used other techniques. The most common measurement modality was the caliper. Mean quality coefficient was 0.57. Eighteen studies (49%) successfully induced sustained lymphedema. Combination of methods seemed to yield the best results, with an overrepresentation of irradiation, the removal of two lymph nodes, and the disruption of both the deep and superficial lymph vessels in the 18 studies.

CONCLUSION

Surgical mouse hindlimb lymphedema models are challenged by two related problems: (1) retaining lymphedema for an extended period, that is, establishing a (chronic) lymphedema model (2) distinguishing lymphedema from post-operative edema. Most studies failed to induce lymphedema and used error-prone measurements. We provide an overview of studies claiming to induce lymphedema and advocate improved research via five evidence-based recommendations to use: (1) a proven lymphedema model; (2) sufficient follow-up time, (3) validated measurement methods; (4) ARRIVE-guidelines; (5) contralateral hindlimb as control.

PPARγ agonist treatment reduces fibroadipose tissue in secondary lymphedema by exhausting fibroadipogenic PDGFRα+ mesenchymal cells

Secondary lymphedema occurs in up to 20% of patients after lymphadenectomy performed for the surgical management of tumors involving the breast, prostate, uterus, and skin. Patients develop progressive edema of the affected extremity due to retention of protein-rich lymphatic fluid. Despite compression therapy, patients progress to chronic lymphedema in which noncompressible fibrosis and adipose tissue are deposited within the extremity. The presence of fibrosis led to our hypothesis that rosiglitazone, a PPARγ agonist that inhibits fibrosis, would reduce fibrosis in a mouse model of secondary lymphedema after hind limb lymphadenectomy. In vivo, rosiglitazone reduced fibrosis in the hind limb after lymphadenectomy. Our findings verified that rosiglitazone reestablished the adipogenic features of TGF-β1-treated mesenchymal cells in vitro. Despite this, rosiglitazone led to a reduction in adipose tissue deposition. Single-cell RNA-Seq data obtained from human tissues and flow cytometric and histological evaluation of mouse tissues demonstrated increased presence of PDGFRα+ cells in lymphedema; human tissue analysis verified these cells have the capacity for adipogenic and fibrogenic differentiation. Upon treatment with rosiglitazone, we noted a reduction in the overall quantity of PDGFRα+ cells and LipidTOX+ cells. Our findings provide a framework for treating secondary lymphedema as a condition of fibrosis and adipose tissue deposition, both of which, paradoxically, can be prevented with a pro-adipogenic agent.

Managing the Morbidity: Individualizing Risk Assessment, Diagnosis, and Treatment Options for Upper Extremity Lymphedema

In the setting where breast cancer-related lymphedema (BCRL) remains a feared and common complication of breast cancer, here we review important factors for the development, diagnosis, prevention, and treatment of BCRL. We find that race/ethnicity affect BCRL development risk, that future studies should focus on understanding the biological reasons behind the increased susceptibility of certain racial minorities to BCRL, that surveillance, early detection, exercise programs, and arm compression can reduce the risk of BCRL, and that surgical techniques to preserve and restore lymphatic drainage being evaluated in randomized trials may become transformative in reducing BCRL risk for high-risk patients.

Etiology and treatment of cancer-related secondary lymphedema

Lymphedema and specifically cancer-related lymphedema is not the main focus for both patients and physicians dealing with cancer. Its etiology is an unfortunate complication of cancer treatment. Although lymphedema treatments have gained an appreciable consensus, many practitioners have developed and prefer their own specific protocols and this is especially true for conventional (manual) versus surgical treatments. This collection of presentations explores the incidence and genetics of cancer-related lymphedema, early detection and monitoring techniques, both conventional and operative treatment options, and the importance and role of exercise for patients with cancer-related lymphedema. These assembled presentations provide valuable insights into the challenges and opportunities presented by cancer-related lymphedema including the latest research, treatments, and exercises available to improve patient outcomes and quality of life.

The emerging importance of lymphatics in health and disease: an NIH workshop report

The lymphatic system (LS) is composed of lymphoid organs and a network of vessels that transport interstitial fluid, antigens, lipids, cholesterol, immune cells, and other materials in the body. Abnormal development or malfunction of the LS has been shown to play a key role in the pathophysiology of many disease states. Thus, improved understanding of the anatomical and molecular characteristics of the LS may provide approaches for disease prevention or treatment. Recent advances harnessing single-cell technologies, clinical imaging, discovery of biomarkers, and computational tools have led to the development of strategies to study the LS. This Review summarizes the outcomes of the NIH workshop entitled "Yet to be Charted: Lymphatic System in Health and Disease," held in September 2022, with emphasis on major areas for advancement. International experts showcased the current state of knowledge regarding the LS and highlighted remaining challenges and opportunities to advance the field.

Therapeutic Potential of the Prolyl Hydroxylase Inhibitor Roxadustat in a Mouse Hindlimb Lymphedema Model

Background: Lymphedema is an intractable disease with no curative treatment available. Conservative treatment is the mainstay, and new drug treatment options are strongly needed. The purpose of this study was to investigate the effect of roxadustat, a prolyl-4-hydroxylase inhibitor, on lymphangiogenesis and its therapeutic effect on lymphedema in a radiation-free mouse hindlimb lymphedema model. Methods and Results: Male C57BL/6N mice (8-10 weeks old) were used for the lymphedema model. Mice were randomized to an experimental group receiving roxadustat or a control group. The circumferential ratio of the hindlimbs was evaluated, and lymphatic flow of the hindlimbs was compared by fluorescent lymphography up to 28 days postoperatively. The roxadustat group showed an early improvement in hindlimb circumference and stasis of lymphatic flow. The number and area of lymphatic vessels on postoperative day 7 were significantly larger and smaller, respectively, in the roxadustat group compared with the control group. Skin thickness and macrophage infiltration on postoperative day 7 were significantly reduced in the roxadustat group compared with the control group. The relative mRNA expression of hypoxia-inducible factor-1α (Hif-1α), vascular endothelial growth factor receptor-3 (VEGFR-3), vascular endothelial growth factor-C (VEGF-C), and Prospero homeobox 1 (Prox1) on postoperative day 4 was significantly higher in the roxadustat group compared with the control group. Conclusions: Roxadustat demonstrated a therapeutic effect in a murine model of hindlimb lymphedema through promotion of lymphangiogenesis through the activation of HIF-1α, VEGF-C, VEGFR-3, and Prox1, suggesting the potential of roxadustat as a therapeutic option in lymphedema.

Topical captopril: a promising treatment for secondary lymphedema

Transforming growth factor-beta 1 (TGF-β1)-mediated tissue fibrosis is an important regulator of lymphatic dysfunction in secondary lymphedema. However, TGF-β1 targeting can cause toxicity and autoimmune complications, limiting clinical utility. Angiotensin II (Ang II) modulates intracellular TGF-β1 signaling, and inhibition of Ang II production using angiotensin-converting enzyme (ACE) inhibitors, such as captopril, has antifibrotic efficacy in some pathological settings. Therefore, we analyzed the expression of ACE and Ang II in clinical lymphedema biopsy specimens from patients with unilateral breast cancer-related lymphedema (BCRL) and mouse models, and found that cutaneous ACE expression is increased in lymphedematous tissues. Furthermore, topical captopril decreases fibrosis, activation of intracellular TGF-β1 signaling pathways, inflammation, and swelling in mouse models of lymphedema. Captopril treatment also improves lymphatic function and immune cell trafficking by increasing collecting lymphatic pumping. Our results show that the renin-angiotensin system in the skin plays an important role in the regulation of fibrosis in lymphedema, and inhibition of this signaling pathway may hold merit for treating lymphedema.

The Future of Lymphedema: Potential Therapeutic Targets for Treatment

Purpose of Review

This review aims to summarize the current knowledge regarding the pharmacological interventions studied in both experimental and clinical trials for secondary lymphedema.

Recent Findings

Lymphedema is a progressive disease that results in tissue swelling, pain, and functional disability. The most common cause of secondary lymphedema in developed countries is an iatrogenic injury to the lymphatic system during cancer treatment. Despite its high incidence and severe sequelae, lymphedema is usually treated with palliative options such as compression and physical therapy. However, recent studies on the pathophysiology of lymphedema have explored pharmacological treatments in preclinical and early phase clinical trials.

Summary

Many potential treatment options for lymphedema have been explored throughout the past two decades including systemic agents and topical approaches to decrease the potential toxicity of systemic treatment. Treatment strategies including lymphangiogenic factors, anti-inflammatory agents, and anti-fibrotic therapies may be used independently or in conjunction with surgical approaches.

Accessory Lymphatic Drainage Pathways on Indocyanine Green Lymphography in Patients with Breast Cancer-Related Lymphedema

BACKGROUND

Current predictive models of lymphedema risk cannot predict with 100% certainty which patients will go on to develop lymphedema and which will not. Patient-specific anatomic and physiologic differences may be the missing factor. The authors hypothesize that patients with accessory lymphatic pathways may have improved lymphatic drainage, resulting in smaller limb volumes.

METHODS

The authors reviewed indocyanine green (ICG) lymphography images of all patients who presented to their institution for evaluation of breast cancer-related lymphedema. Patients with unilateral upper extremity lymphedema, a full set of bilateral limb measurements, and ICG images of both limbs were included. Other variables of interest included patient demographics and length of follow-up. Patients with accessory pathways were determined independently, and conflicts were resolved with discussion. Abnormal images were also evaluated for common drainage pathways.

RESULTS

Thirty patients were identified as having accessory lymphatic drainage pathways. These patients had significantly smaller limb volume differences [8.19% (SD, 11.22)] compared with patients who did not exhibit these pathways [20.74% (SD, 19.76); P < 0.001]. The most common pathway was absence or rerouting of the radial bundle to the ulnar or volar bundles ( n = 16).

CONCLUSIONS

The ability to create accessory lymphatic drainage pathways may be associated with improved lymphatic drainage, resulting in smaller limb volumes. Furthermore, certain drainage pathways appear to be more common than others. Description of these pathways should be considered for inclusion in ICG lymphography image grading criteria. Further study is needed to clarify the nature of these pathways and whether these pathways affect subjective symptoms and quality of life.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Effects of an early intervention with Hyperbaric Oxygen Treatment on arm lymphedema and quality of life after breast cancer-an explorative clinical trial

PURPOSE

Lymphedema (LE) is a common complication after breast cancer treatment, which negatively affects the quality of life (QOL). Hyperbaric Oxygen Treatment (HBOT) is an established treatment for radiation-induced tissue injury, but evidence of effect on breast cancer-related LE is inconclusive. We aimed to explore effects of HBOT on early breast cancer-related LE and the implications for QOL.

METHODS

We invited women with breast cancer treated with surgery, axillary dissection and radiotherapy, who had participated in a randomized controlled trial and who presented with LE 1 year after surgery. In a prospective observational study design, change in LE was assessed with perometry, dual-energy X-ray absorptiometry (DXA) and lymphoscintigraphy, and QOL by validated self-report scales. Participants were offered 40 sessions of HBOT on every weekday for 8 weeks and were followed for 6 months.

RESULTS

Out of 50 eligible participants, 20 women accepted participation. Nineteen women initiated and completed treatment and follow-up. None of the objective measures of LE severity showed consistent changes during the study period, but participants reported significant improvements in QOL (physical functioning, fatigue, insomnia and breast and arm symptoms), with improvements peaking at 6-month follow-up.

CONCLUSION

Participants receiving HBOT experienced improved QOL without consistently significant changes in arm mass, volume or lymphatic drainage. These results call for studies into differential effect in patient sub-groups, and a large-scale, randomized placebo-controlled trial with long-term follow-up to assess the effect of HBOT in patients with soft tissue radiation injuries after breast cancer seems warranted.

TRIAL REGISTRATION

Danish Health and Medicines Authority, EUDRACT no. 2015-000,604-25 Ethical committee of the Capitol Region, No. R96-A6604-14-S22.

The Impact of Lymphedema on Patient-Reported Outcomes After Breast Reconstruction: A Preliminary Propensity Score-Matched Analysis

BACKGROUND

Studies on the impact of secondary lymphedema on patient-reported satisfaction and quality of life following postmastectomy breast reconstruction are limited by their heterogeneity. We aimed to reduce heterogeneity in study sample populations and compare BREAST-Q Reconstruction Module scores of patients with lymphedema matched to patients without lymphedema.

METHODS

We identified patients who underwent postmastectomy breast reconstruction from 2009 to 2017 and performed a propensity score-matched analysis to compare patient-reported outcomes of patients who developed lymphedema with those who did not. Matched covariates included age, body mass index, race/ethnicity, smoking history, radiation or chemotherapy exposure, postoperative infection, and reconstruction modality and laterality. Outcomes of interest were pre- and postoperative BREAST-Q scores for Satisfaction with Breasts, Physical Well-being of the Chest, Sexual Well-Being, and Psychosocial Well-Being; the minimal clinically important difference (MCID) was four points.

RESULTS

Matched cohorts included 322 patients per group. Preoperative BREAST-Q scores did not differ between lymphedema and non-lymphedema matched cohorts. Postoperative BREAST-Q scores were significantly lower in lymphedema patients: Physical Well-Being of the Chest (all time points), Satisfaction with Breast (at 1 and 2 years), Sexual Well-Being (at 2 years), and Psychosocial Well-Being (at 2 and 3 years). All significant differences in average scores were greater than the MCID.

CONCLUSIONS

Patients with breast cancer-related lymphedema reported significantly lower Physical Well-Being of the Chest, Satisfaction with Breasts, Sexual Well-Being, and Psychosocial Well-Being at various time points. Our findings may prove useful for patient counseling and justify the need for further research on the prevention and treatment of this devastating disease.

Therapeutic Lymphangiogenesis Is a Promising Strategy for Secondary Lymphedema

Secondary lymphedema is caused by lymphatic insufficiency (lymphatic drainage failure) following lymph node dissection during the surgical treatment or radiation therapy of breast or pelvic cancer. The clinical problems associated with lymphedema are reduced quality of life in terms of appearance and function, as well as the development of skin ulcers, recurrent pain, and infection. Currently, countermeasures against lymphedema are mainly physical therapy such as lymphatic massage, elastic stockings, and skin care, and there is no effective and fundamental treatment with a highly recommended grade. Therefore, there is a need for the development of a fundamental novel treatment for intractable lymphedema. Therapeutic lymphangiogenesis, which has been attracting attention in recent years, is a treatment concept that reconstructs the fragmented lymphatic network to recover lymphatic vessel function and is revolutionary to be a fundamental cure. This review focuses on the translational research of therapeutic lymphangiogenesis for lymphedema and outlines the current status and prospects in the development of therapeutic applications.

Risk factors for the development of severe breast cancer-related lymphedema: a retrospective cohort study

BACKGROUND

Severe lymphedema presents a challenge in terms of treatment due to the significant formation of scar tissue that accompanies it. The aim of this study was to identify intraoperative and preoperative risk factors of severe lymphedema and to develop a nomogram for estimating the risk of severe lymphedema within 3 years of surgery.

METHOD

Data was collected from a retrospective cohort of 326 patients with BCRL at the Zhejiang Cancer Hospital from November 2015 to November 2018. Univariate and multivariate logistic regression analysis was conducted to identify predictive indicators of severe lymphedema. A nomogram was developed to further improve the clinical applicability.

RESULTS

In the retrospective cohort, the ratio of severe/non-severe lymphedema within 3 years of surgery was 1:3. Independent risk factors for severe lymphedema were determined to be age, positive lymph nodes, interpectoral (Rotter's) lymph nodes (IPNs) dissection, and educational level. IPNs dissection was found to contribute greatly to the development of severe lymphedema with a higher odds ratio (7.76; 95% CI: 3.87-15.54) than other risk factors. A nomogram was developed by integrating age, positive lymph nodes, IPNs dissection, and educational level, which yielded a C-index of 0.810 and 0.681 in the training and validation cohort, respectively. This suggested a moderate performance of the nomogram in predicting the risk of severe lymphedema within 3 years of surgery. The cut-off values of the low-, medium- and high-risk probabilities were 0.0876 and 0.3498, and the severe lymphedema exhibited a significantly higher risk probability as compared with the non-severe lymphedema.

CONCLUSION

This study identified the risk factors of severe lymphedema and highlighted the substantial contribution of IPNs dissection to the severity of lymphedema.

Body mass index increases the risk of breast cancer-related lymphedema at 6-18 months after surgery: a retrospective study

PURPOSE

Breast cancer-related lymphedema (BCRL) is an incurable complication occurring after breast cancer treatment. The influence of obesity/overweight on the development of BCRL at different points after surgery was seldom verified. We aimed to determine the cut-off BMI/weight value associated with an increased risk of BCRL at different postoperative time in Chinese breast cancer survivors.

METHODS

Patients who underwent breast surgery plus axillary lymph node dissection (ALND) were retrospectively evaluated. Disease and treatment characteristics of participants were collected. BCRL was diagnosed by circumference measurements. Univariate and multivariable logistic regression was used to assess the relationship of lymphedema risk with BMI/weight and other disease- and treatment-related factors.

RESULTS

518 patients were included. Lymphedema occurred more frequently among breast cancer patients with preoperative BMI ≥ 25 kg/m² (37.88%) than among those with preoperative BMI < 25 kg/m²(23.32%), with significant differences at 6-12 and 12-18 months after surgery (χ² = 23.183, P = 0.000; χ² = 5.279, P = 0.022). By multivariable logistics analysis, preoperative BMI ≥ 30 kg/m² presented a significantly greater risk of lymphedema than a preoperative BMI < 25 kg/m² (OR [95% CI] = 2.928 [1.565, 5.480]). Other factors, including radiation (breast/chest wall + axilla vs. none: OR [95% CI] = 3.723[2.271-6.104]), was an independent risk factor for lymphedema.

CONCLUSIONS

Preoperative obesity was an independent risk factor for BCRL in Chinese breast cancer survivors, and a preoperative BMI ≥ 25 kg/m² indicated greater likelihood of lymphedema development within 6-18 months postoperatively.

Prophylactic Lymphaticovenous Anastomosis Performed with Lymphadenectomy is Oncologically Safe for Melanoma

BACKGROUND

A major concern of lymphaticovenous anastomosis (LVA), which has not been studied, is increased risk of metastasis. Melanoma patients with macrometastatic lymph node disease represent a high-risk group for recurrence and metastasis. On the basis of a literature review, this present study is the first to evaluate the impact of prophylactic LVA on cancer survival and recurrence.

METHODS

This was a comparison study of patients with cutaneous melanoma who underwent therapeutic lymphadenectomy alone (comparison group) or combined with prophylactic LVA (LVA group) between 2014 and 2020. A single surgeon performed all cancer resections, therapeutic lymphadenectomies, and LVA. Exclusion criteria included non-melanoma skin cancers, stage IV cancers before lymphadenectomy, microscopic lymphatic disease (i.e., positive sentinel node biopsy was the sole indication for lymph node dissection), or follow-up time less than 12 months unless the patient died earlier owing to melanoma-related complications.

RESULTS

This study included 23 patients in the LVA group and 22 consecutive patients in the comparison group. The two groups were similar in age, sex, and cancer stages. The comparison group had longer follow-up times (median 67.62 versus 29.73 months in the LVA group; p < 0.01). Average size of largest metastatic lymph node was 45.91 ± 35.03 mm and 44.54 ± 23.32 mm in the LVA and comparison groups, respectively (p = 0.99). There were no differences in OS, DMFS, and RFS times after more than 2 years of follow-up since the index surgery.

CONCLUSION

Prophylactic LVA performed for macrometastatic melanoma is not a strong risk factor for relapse and metastasis.

LEVEL OF EVIDENCE

II Therapeutic.

Comparison of the Effectiveness of Liposuction for Lower Limb versus Upper Limb Lymphedema

OBJECTIVE

Liposuction is the most frequently performed debulking procedure in patients with lymphedema. However, it remains uncertain whether liposuction is equally effective for upper extremity lymphedema (UEL) and lower extremity lymphedema (LEL). In this study, we retrospectively compared the effectiveness of liposuction according to whether it was performed for LEL or UEL, and identified factors associated with outcomes.

MATERIALS AND METHODS

All patients had been treated at least once by lymphovenous anastomosis or vascularized lymphatic transplant before liposuction but without sufficient volume reduction. The patients were divided into an LEL group and a UEL group, and then subdivided further according to whether they completed their planned compression therapy into an LEL compliance group, an LEL non-compliance group, a UEL compliance group, and a UEL non-compliance group. The reduction rates in LEL (REL) and in UEL (REU) were compared between the groups.

RESULTS

In total, 28 patients with unilateral lymphedema were enrolled (LEL compliance group, n = 12; LEL non-compliance group, n = 6; UEL compliance group, n = 10; UEL non-compliance group, n = 0). The non-compliance rate was significantly higher in the LEL group than in the UEL group (p = 0.04). REU was significantly higher than REL (100.1 ± 37.3% vs. 59.3 ± 49.4%; p = 0.03); however, there was no significant difference between REL in the LEL compliance group (86 ± 31%) and REU in the UEL group (101 ± 37%) (p = 0.32).

CONCLUSION

Liposuction seems to be more effective in UEL than in LEL, probably because the compression therapy required for management after liposuction is easier to implement for UEL. The lower pressure and smaller coverage area required for postoperative management after liposuction in the upper limb may explain why liposuction is more effective in UEL than in LEL.

Regulating Lymphatic Vasculature in Fibrosis: Understanding the Biology to Improve the Modeling

Fibrosis occurs in many chronic diseases with lymphatic vascular insufficiency (e.g., kidney disease, tumors, and lymphedema). New lymphatic capillary growth can be triggered by fibrosis-related tissue stiffening and soluble factors, but questions remain for how related biomechanical, biophysical, and biochemical cues affect lymphatic vascular growth and function. The current preclinical standard for studying lymphatics is animal modeling, but in vitro and in vivo outcomes often do not align. In vitro models can also be limited in their ability to separate vascular growth and function as individual outcomes, and fibrosis is not traditionally included in model design. Tissue engineering provides an opportunity to address in vitro limitations and mimic microenvironmental features that impact lymphatic vasculature. This review discusses fibrosis-related lymphatic vascular growth and function in disease and the current state of in vitro lymphatic vascular models while highlighting relevant knowledge gaps. Additional insights into the future of in vitro lymphatic vascular models demonstrate how prioritizing fibrosis alongside lymphatics will help capture the complexity and dynamics of lymphatics in disease. Overall, this review aims to emphasize that an advanced understanding of lymphatics within a fibrotic disease-enabled through more accurate preclinical modeling-will significantly impact therapeutic development toward restoring lymphatic vessel growth and function in patients.

A Novel Dressing Composed of Adipose Stem Cells and Decellularized Wharton's Jelly Facilitated Wound Healing and Relieved Lymphedema by Enhancing Angiogenesis and Lymphangiogenesis in a Rat Model

Lymphedema causes tissue swelling due to the accumulation of lymphatic fluid in the tissue, which delays the process of wound-healing. Developing effective treatment options of lymphedema is still an urgent issue. In this study, we aim to fabricate tissue-engineered moist wound dressings with adipose stem cells (ASCs) and decellularized Wharton's jelly (dWJ) from the human umbilical cord in order to ameliorate lymphedema. Rat ASCs were proliferated and an apparent layer was observed on dWJ at day 7 and 14. A rat tail lymphedema model was developed to evaluate the efficacy of the treatment. Approximately 1 cm of skin near the base of the rat tail was circularly excised. The wounds were treated by secondary healing (control) (n = 5), decellularized Wharton's jelly (n = 5) and ASC-seeded dWJ (n = 5). The wound-healing rate and the tail volume were recorded once a week from week one to week five. Angiogenesis and lymphangiogenesis were assessed by immunochemistry staining with anti-CD31 and anti-LYVE1. The results showed that the wound-healing rate was faster and the tail volume was lesser in the ASC-seeded dWJ group than in the control group. More CD31+ and LYVE-1+ cells were observed at the wound-healing area in the ASC-seeded dWJ group than in the control group. This proves that tissue-engineered moist wound dressings can accelerate wound-healing and reduce lymphedema by promoting angiogenesis and lymphangiogenesis.

Effect of Probiotics in Breast Cancer: A Systematic Review and Meta-Analysis

Probiotics may have the potential to protect against breast cancer, partly through systemic immunomodulatory action and active impact upon intestinal microbiota. Given a few clinical studies on their curative role, we conducted a systematic review of the potential effects of probiotics in breast cancer patients and survivors of breast cancer, aiming to support further clinical studies. A literature search was performed using PubMed, Embase, and the CENTRAL databases from inception through to March 2022. A total of eight randomized clinical trials were identified from thirteen articles published between 2004 and 2022. We evaluated quality-of-life measures, observed bacterial species and diversity indices, probiotic-related metabolites, inflammatory biomarkers, and other responses in breast cancer patients and survivors. Results were synthesized qualitatively and quantitatively using random-effects meta-analysis. Different probiotics supplements utilized included Lactobacillus species alone (Lacto), with or without estriol; probiotic combinations of Lactobacillus with Bifidobacterium (ProLB), with or without prebiotic fructooligosaccharides (FOS); ProLB plus Streptococcus and FOS (ProLBS + FOS); and ProLB plus Enterococcus (ProLBE). We found that use of ProLBS with FOS in breast cancer patients and use of ProLBE in survivors of breast cancer show potential benefits in countering obesity and dyslipidemia. ProLBS with FOS use decreases pro-inflammatory TNF-α in breast cancer survivors and improves quality of life in those with breast-cancer-associated lymphedema. Supplementing probiotics capsules (10⁹ CFU) with a prebiotic and using an intake duration of 10 weeks could provide a better approach than probiotics alone.

Lymphatic Microsurgical Preventive Healing Approach for the Primary Prevention of Lymphedema: A 4-Year Follow-Up

BACKGROUND

Axillary lymph node dissection (ALND) remains the leading cause of lymphedema nationally, and there is still no cure for the disease. The lymphatic microsurgical preventive healing approach (LYMPHA) is a promising option for lymphedema prophylaxis in patients undergoing ALND, but long-term outcomes of the LYMPHA are not well established.

METHODS

The authors conducted a retrospective review of patients undergoing ALND at their center from November of 2012 to November of 2016 and assembled two cohorts, those who received the LYMPHA and those who did not (non-LYMPHA). Patient data were collected to evaluate lymphedema risk and long-term lymphedema incidence of each group.

RESULTS

Forty-five women were included in both our LYMPHA and non-LYMPHA cohorts. Mean body mass index (27.7 kg/m2 versus 29.9 kg/m2; P = 0.15) and radiation therapy rates (60.0% versus 68.9%; P = 0.51) did not differ between groups. Non-LYMPHA patients underwent complete mastectomy more frequently than LYMPHA patients (97.8% versus 77.8%; P = 0.007), but had a similar number of nodes removed during ALND (14.4 versus 15.8; P = 0.32). Median follow-up time was greater than 4 years for both LYMPHA and non-LYMPHA groups (57.0 months versus 63.0 months; P = 0.07). Overall, lymphedema incidence was 31.1% in the LYMPHA group and 33.3% in the non-LYMPHA group (P > 0.99). No significant differences in lymphedema incidences were observed between the LYMPHA and non-LYMPHA groups for patients with obesity, patients who received radiation therapy, or patients with obesity who also received radiation therapy (P > 0.05 for all subgroups).

CONCLUSIONS

The LYMPHA may not prevent lymphedema long-term in patients who undergo ALND. More long-term studies are needed to determine the true potential of the procedure.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

The Vicious Circle of Stasis, Inflammation, and Fibrosis in Lymphedema

SUMMARY

Lymphedema is a progressive disease of the lymphatic system arising from impaired lymphatic drainage, accumulation of interstitial fluid, and fibroadipose deposition. Secondary lymphedema resulting from cancer treatment is the most common form of the disease in developed countries, affecting 15% to 40% of patients with breast cancer after lymph node dissection. Despite recent advances in microsurgery, outcomes remain variable and, in some cases, inadequate. Thus, development of novel treatment strategies is an important goal. Research over the past decade suggests that lymphatic injury initiates a chronic inflammatory response that regulates the pathophysiology of lymphedema. T-cell inflammation plays a key role in this response. In this review, the authors highlight the cellular and molecular mechanisms of lymphedema and discuss promising preclinical therapies.

Keratinocytes coordinate inflammatory responses and regulate development of secondary lymphedema

Epidermal changes are histological hallmarks of secondary lymphedema, but it is unknown if keratinocytes contribute to its pathophysiology. Using clinical lymphedema specimens and mouse models, we show that keratinocytes play a primary role in lymphedema development by producing T-helper 2 (Th2) -inducing cytokines. Specifically, we find that keratinocyte proliferation and expression of protease-activated receptor 2 (PAR2) are early responses following lymphatic injury and regulate the expression of Th2-inducing cytokines, migration of Langerhans cells, and skin infiltration of Th2-differentiated T cells. Furthermore, inhibition of PAR2 activation with a small molecule inhibitor or the proliferation inhibitor teriflunomide (TF) prevents activation of keratinocytes stimulated with lymphedema fluid. Finally, topical TF is highly effective for decreasing swelling, fibrosis, and inflammation in a preclinical mouse model. Our findings suggest that lymphedema is a chronic inflammatory skin disease, and topically targeting keratinocyte activation may be a clinically effective therapy for this condition.

A new label-free optical imaging method for the lymphatic system enhanced by deep learning

Our understanding of the lymphatic vascular system lags far behind that of the blood vascular system, limited by available imaging technologies. We present a label-free optical imaging method that visualizes the lymphatic system with high contrast. We developed an orthogonal polarization imaging (OPI) in the shortwave infrared range (SWIR) and imaged both lymph nodes and lymphatic vessels of mice and rats in vivo through intact skin, as well as human mesenteric lymph nodes in colectomy specimens. By integrating SWIR-OPI with U-Net, a deep learning image segmentation algorithm, we automated the lymph node size measurement process. Changes in lymph nodes in response to cancer progression were monitored in two separate mouse cancer models, through which we obtained insights into pre-metastatic niches and correlation between lymph node masses and many important biomarkers. In a human pilot study, we demonstrated the effectiveness of SWIR-OPI to detect human lymph nodes in real time with clinical colectomy specimens.

One Sentence Summary

We develop a real-time high contrast optical technique for imaging the lymphatic system, and apply it to anatomical pathology gross examination in a clinical setting, as well as real-time monitoring of tumor microenvironment in animal studies.

Efficacy of immunotherapy with combination of cryotherapy and topical imiquimod for treatment of Kaposi sarcoma

Multiple treatment modalities for Kaposi sarcoma (KS) have been reported, including chemotherapy, radiation therapy, surgical excision, electrochemotherapy, and cryotherapy. Common topical treatments include timolol, imiquimod, and alitretinoin. We searched our institutional database for patients with ICD-9 or 10 codes for KS seen by a dermatologist with experience in KS management from July 1, 2004 to January 1, 2022. We screened patient charts to include patients who received combination therapy of cryotherapy followed by topical imiquimod three times a week for 2 months (n = 9). Patients were followed in the clinic every 3 months. Time to resolution was assessed by photographic evidence of resolution as determined by a dermatologist and corroborated with clinical documentation in patient charts. Median age (IQR) at KS diagnosis was 58 (27.5) years. All patients were male (n = 9, 100%). Majority were white (n = 7, 78%) and non-Hispanic (n = 8, 89%). Five (56%) had classic KS, one (11%) had HIV-associated KS, and three (33%) were HIV-negative men who have sex with men. Median time to resolution was 30.5 weeks, with a median of two treatments. In our study, 93% (n = 42/45) of lesions and 89% (n = 8/9) of patients experienced complete resolution during a median (range) duration of follow-up of 58 (13-209) weeks. Side effects were limited to pain during cryotherapy, occasional blister formation after cryotherapy, and mild inflammation due to imiquimod. No infections were observed. Combination therapy of cryotherapy and topical imiquimod may be an efficacious and comparatively low-risk treatment for limited, cutaneous KS.

Lymphatic endothelial cell RXRα is critical for 9-cis-retinoic acid-mediated lymphangiogenesis and prevention of secondary lymphedema

Secondary lymphedema is a debilitating disease characterized by abnormal soft tissue swelling and caused by lymphatic system dysfunction. Despite a high prevalence of secondary lymphedema after cancer treatments, current management is supportive and there are no approved therapeutic agents that can thwart disease progression. We have previously demonstrated that 9-cis-retinoic acid (9-cisRA) has the potential to be repurposed for lymphedema as it mitigates disease by promoting lymphangiogenesis at the site of lymphatic injury. Although the efficacy of 9-cisRA has been demonstrated in previous studies, the mechanism of action is not completely understood. In this study, we demonstrate that when RXRα is specifically deleted in lymphatic endothelial cells, 9-cisRA fails to induce lymphangiogenesis in vitro and prevent pathologic progression of postsurgical lymphedema in vivo. These findings demonstrate that downstream nuclear receptor RXRα plays a critical role in the therapeutic efficacy of 9-cisRA in postsurgical lymphedema.

Development and validation of a risk prediction model for breast cancer-related lymphedema in postoperative patients with breast cancer

OBJECTIVE

Breast cancer-related lymphedema (BCRL) is a common post-operative complication in patients with breast cancer. Here, we sought to develop and validate a predictive model of BCRL in Chinese patients with breast cancer.

METHODS

Clinical and demographic data on patients with breast cancer were collected between 2016 and 2021 at a Cancer Hospital in China. A nomogram for predicting the risk of lymphedema in postoperative patients with breast cancer was constructed and verified using R 3.5.2 software. Model performance was evaluated using area under the ROC curve (AUC) and goodness-of-fit statistics, and the model was internally validated.

RESULTS

A total of 1732 postoperative patients with breast cancer, comprising 1212 and 520 patients in the development and validation groups, respectively, were included. Of these 438 (25.39%) developed lymphedema. Significant predictors identified in the predictive model were time since breast cancer surgery, level of lymph node dissection, number of lymph nodes dissected, radiotherapy, and postoperative body mass index. At the 31.9% optimal cut-off the model had AUC values of 0.728 and 0.710 in the development and validation groups, respectively. Calibration plots showed a good match between predicted and observed rates. In decision curve analysis, the net benefit of the model was better between threshold probabilities of 10%-80%.

CONCLUSION

The model has good discrimination and accuracy for lymphedema risk assessment, which can provide a reference for individualized clinical prediction of the risk of BCRL. Multicenter prospective trials are required to verify the predictive value of the model.

Prolymphangiogenic Effects of 9-cis Retinoic Acid Are Enhanced at Sites of Lymphatic Injury and Dependent on Treatment Duration in Experimental Postsurgical Lymphedema

Background: Patients undergoing surgical treatment for solid tumors are at risk for development of secondary lymphedema due to intraoperative lymphatic vessel injury. The damaged lymphatic vessels fail to adequately regenerate and lymphatic obstruction leads to fluid and protein accumulation in the interstitial space and chronic lymphedema develops as a result. There are currently no effective pharmacological agents that reduce the risk of developing lymphedema or treat pre-existing lymphedema, and management is largely palliative. The present study investigated the efficacy of various 9-cis retinoic acid (9-cis RA) dosing strategies in reducing postsurgical lymphedema by utilizing a well-established mouse tail lymphedema model. Methods and Results: Short-duration treatment with 9-cis RA did not demonstrate a significant reduction in postoperative tail volume, nor an improvement in lymphatic clearance. However, long-term treatment with 9-cis RA resulted in decreased overall tail volume, dermal thickness, and epidermal thickness, with an associated increase in functional lymphatic clearance and lymphatic vessel density, assessed by LYVE-1 immunostaining, compared with control. These effects were seen at the site of lymphatic injury, with no significant changes observed in uninjured sites such as ear skin and the diaphragm. Conclusions: Given the reported results indicating that 9-cis RA is a potent promoter of lymphangiogenesis and improved lymphatic clearance at sites of lymphatic injury, investigation of postoperative 9-cis RA administration to patients at high risk of developing lymphedema may demonstrate positive efficacy and reduced rates of postsurgical lymphedema.

Approach to Lymphedema Management

Millions of people worldwide suffer from lymphedema. In developed nations, lymphedema most commonly stems secondarily from oncologic treatment, but may also result from trauma. More recently, lymphedema has been identified in patients after gender-affirmation phalloplasty reconstruction. Regardless of the etiology, the underlying pathophysiology involves blockage of lymphatic flow, resulting in lymph stasis, thus triggering a cascade of inflammation culminating in fibrosis and adipose deposition. Recent technical advances led to the refinement of physiologic and reductive surgeries-including lymphovenous anastomosis and free functional lymphatic transfer, which collectively encompass a variety of flap procedures including lymph node transfer, lymph channel transfer, and lymphatic system transfer. This article provides a summary of our approach in the assessment and management of the lymphedema patient, including detailed intraoperative photography and imaging, in addition to advanced technical considerations in physiologic reconstruction.

Doxycycline for the treatment of breast cancer-related lymphedema

Purpose: Secondary lymphedema is a common complication of cancer treatment for which no effective drug treatments yet exist. Level I clinical data suggests that doxycycline is effective for treating filariasis-induced lymphedema, in which it decreases tissue edema and skin abnormalities; however, this treatment has not been tested for cancer-related lymphedema. Over the past year, we used doxycycline in an off-label manner in patients with breast cancer-related secondary lymphedema. The purpose of this report was to retrospectively analyze the efficacy of this treatment. Methods: Patients who presented to our lymphedema clinic between January 2021 and January 2022 were evaluated, and barring allergies or contraindications to doxycycline treatment, were counseled on the off-label use of this treatment. Patients who wished to proceed were treated with doxycycline (200 mg given orally once daily) for 6 weeks. After IRB approval of this study, lymphedema outcomes were retrospectively reviewed. Results: Seventeen patients with a mean follow-up of 17.0 ± 13.2 weeks were identified in our retrospective review. Although doxycycline treatment had no significant effect on relative limb volume change or L-Dex scores, we found a significant improvement in patient-reported quality of life. Analysis of patient responses to the Lymphedema Life Impact Scale showed a significant improvement in the total impairment score due to improvements in the physical and psychological well-being subscales (p = 0.03, p = 0.03, p = 0.04, respectively). Conclusion: This small, retrospective study did not show significant improvements in limb volume or L-Dex scores in patients with breast cancer-related lymphedema treated with doxycycline. However, our patients reported improvements in quality-of-life measures using a validated lymphedema patient-reported outcome instrument. Our results suggest that doxycycline may be of use in patients with breast cancer-related lymphedema; however, larger and more rigorous studies are needed.

Single and combined impacts of irradiation and surgery on lymphatic vasculature and fibrosis associated to secondary lymphedema

Lymphedema (LD) refers to a condition of lymphatic dysfunction associated with excessive fluid accumulation, fibroadipose tissue deposition and swelling. In industrialized countries, LD development mainly results from a local disruption of the lymphatic network by an infection or cancer-related surgery (secondary LD). In the absence of efficient therapy, animal models are needed to decipher the cellular and molecular mechanisms underlying LD and test putative drugs. In this study, we optimized and characterized a murine model of LD that combines an irradiation of the mice hind limb and a radical surgery (lymph node resection associated to lymphatic vessel ligation). We investigated the respective roles of irradiation and surgery in LD formation by comparing their impacts, alone or in combination (with different intervention sequences), on eight different features of the pathology: swelling (paw thickness), indocyanine green (ICG) clearance, lymphatic vasculature remodeling, epidermal and dermal thickening, adipocyte accumulation, inflammatory cell infiltration and collagen deposition. This study supports the importance of radiation prior to surgery to experimentally induce a rapid, severe and sustained tissue remodeling harboring the different hallmarks of LD. We provide the first experimental evidence for an excessive deposition of periostin (POSTN) and tenascin-C (TNC) in LD. Through a computerized method of digital image quantification, we established the spatial map of lymphatic expansion, as well as collagen, POSTN and TNC deposition in papillary and reticular dermis of lymphedematous skins. This mouse model is available to study the patho-physiology of LD and test potential therapeutic targets.

A Prospective Study on the Safety and Efficacy of Vascularized Lymph Node Transplant

PURPOSE

While vascularized lymph node transplant (VLNT) has gained popularity, there are a lack of prospective long-term studies and standardized outcomes. The purpose of this study was to evaluate the safety and efficacy of VLNT using all available outcome measures.

METHODS

This was a prospective study on all consecutive patients who underwent VLNT. Outcomes were assessed with 2 patient-reported outcome metrics, limb volume, bioimpedance, need for compression, and incidence of cellulitis.

RESULTS

There were 89 patients with the following donor sites: omentum (73%), axilla (13%), supraclavicular (7%), groin (3.5%). The mean follow-up was 23.7±12 months. There was a significant improvement at 2 years postoperatively across all outcome measures: 28.4% improvement in the Lymphedema Life Impact Scale, 20% average reduction in limb volume, 27.5% improvement in bioimpedance score, 93% reduction in cellulitis, and 34% of patients no longer required compression. Complications were transient and low without any donor site lymphedema.

CONCLUSIONS

VLNT is a safe and effective treatment for lymphedema with significant benefits fully manifesting at 2 years postoperatively. Omentum does not have any donor site lymphedema risk making it an attractive first choice.

Which physical therapy intervention is most effective in reducing secondary lymphoedema associated with breast cancer? Protocol for a systematic review and network meta-analysis

INTRODUCTION

Lymphoedema associated with breast cancer is caused by an interruption of the lymphatic system, together with factors such as total mastectomy, axillary dissection, positive lymph nodes, radiotherapy, use of taxanes and obesity. Physiotherapy treatment consists of complex decongestive therapy, manual lymphatic drainage and exercises, among other interventions. Currently, there are several systematic review and randomised controlled trials that evaluate the efficacy of these interventions. However, at present, there are no studies that compare the effectiveness of all these physical therapy interventions. The purpose of this study is to determine which physical therapy treatment is most effective in reducing breast cancer-related lymphoedema, improving quality of life and reducing pain.

METHODS AND ANALYSIS

MEDLINE, PEDro, CINAHL, EMBASE, LILACS and Cochrane Central Register of Controlled Trials will be searched for reports of randomised controlled trials published from database inception to June 2022. We will only include studies that are written in English, Spanish and Portuguese. We will also search grey literature, preprint servers and clinical trial registries. The primary outcomes are reduction of secondary lymphoedema associated with breast cancer, improvements in quality of life and pain reduction. The risk of bias of individual studies will be evaluated using the Cochrane Risk of Bias 2.0 Tool. A network meta-analysis will be performed using a random-effects model. First, pairs will be directly meta-analysed and indirect comparisons will be made between the different physical therapy treatments. The GRADE system will be used to assess the overall quality of the body of evidence associated with the main results.

ETHICS AND DISSEMINATION

This protocol does not require approval from an ethics committee. The results will be disseminated via peer-reviewed publications.

PROSPERO REGISTRATION NUMBER

CDR42022323541.

Effectiveness of Mobiderm® bandages in the treatment of cancer-related secondary lymphedema: A pilot study

Secondary lymphedema is a clinically incurable disease that commonly occurs following surgical cancer treatment and/or radiation. One of the most common forms of lymphedema treatment is complete decongestive therapy (CDT). This study aimed to investigate the clinical effects of new compression bandages (Mobiderm® bandages) in patients with secondary lymphedema after cancer treatment. This study included 17 patients with ipsilateral limb lymphedema after cancer treatment (one male and 16 female patients; age, 45-80 years). Patients were divided into the Mobiderm® bandage group (n = 9) and classical bandage group (n = 8). The International Society of Lymphology (ISL) stage was also evaluated. Limb circumference was measured at 5 to 6 sites per limb to identify the maximal circumference difference (MCD) between the affected and unaffected limbs. Pre-and posttreatment MCD were analyzed. After intensive CDT, both the Mobiderm® bandage group (1.2 ± 0.56 cm) and classical bandage group (0.85 ± 0.40 cm) had a significant decrease in MCD compared to pretreatment (P < .05). However, in patients with ISL stage 2, the mean MCD decrease rate was greater in the Mobiderm® bandage group (22.82 ± 10.92 %) than in the classical bandage group (12.18 ± 8.1 1%)(P = .045). Both new bandages (Mobiderm® bandages and classical bandages) reduced the circumference of limb edema in patients with secondary lymphedema after cancer treatment. This study findings suggest that Mobiderm® bandages as an alternative modality for controlling ISL stage 2 lymphedema.

Low Efficacy of Genetic Tests for the Diagnosis of Primary Lymphedema Prompts Novel Insights into the Underlying Molecular Pathways

Lymphedema is a chronic inflammatory disorder caused by ineffective fluid uptake by the lymphatic system, with effects mainly on the lower limbs. Lymphedema is either primary, when caused by genetic mutations, or secondary, when it follows injury, infection, or surgery. In this study, we aim to assess to what extent the current genetic tests detect genetic variants of lymphedema, and to identify the major molecular pathways that underlie this rather unknown disease. We recruited 147 individuals with a clinical diagnosis of primary lymphedema and used established genetic tests on their blood or saliva specimens. Only 11 of these were positive, while other probands were either negative (63) or inconclusive (73). The low efficacy of such tests calls for greater insight into the underlying mechanisms to increase accuracy. For this purpose, we built a molecular pathways diagram based on a literature analysis (OMIM, Kegg, PubMed, Scopus) of candidate and diagnostic genes. The PI3K/AKT and the RAS/MAPK pathways emerged as primary candidates responsible for lymphedema diagnosis, while the Rho/ROCK pathway appeared less critical. The results of this study suggest the most important pathways involved in the pathogenesis of lymphedema, and outline the most promising diagnostic and candidate genes to diagnose this disease.

Current Understanding of Pathological Mechanisms of Lymphedema

Significance: Lymphedema is a common disease that affects hundreds of millions of people worldwide with significant financial and social burdens. Despite increasing prevalence and associated morbidities, the mainstay treatment of lymphedema is largely palliative without an effective cure due to incomplete understanding of the disease. Recent Advances: Recent studies have described key histological and pathological processes that contribute to the progression of lymphedema, including lymphatic stasis, inflammation, adipose tissue deposition, and fibrosis. This review aims to highlight cellular and molecular mechanisms involved in each of these pathological processes. Critical Issues: Despite recent advances in the understanding of the pathophysiology of lymphedema, cellular and molecular mechanisms underlying the disease remains elusive due to its complex nature. Future Directions: Additional research is needed to gain a better insight into the cellular and molecular mechanisms underlying the pathophysiology of lymphedema, which will guide the development of therapeutic strategies that target specific pathology of the disease.

Retrograde Lymph Flow in the Lymphatic Vessels in Limb Lymphedema

OBJECTIVE

Retrograde movement of lymph due to damaged and/or incompetent valves in the lymphatic vessels has been considered a pathological feature of lymphedema. This study aimed to determine the prevalence of retrograde lymph flow and the characteristics of patients with this condition using indocyanine green (ICG) lymphography.

METHODS

An audit of 679 patients with upper or lower limb swelling who underwent ICG lymphography was undertaken over a 4-year period. Harvey's technique was applied to identify retrograde flow in the lymph collecting vessel during ICG lymphography. The characteristics of patients with retrograde lymph flow were recorded.

RESULTS

Twenty-one patients (3.7%, lower limb: n=19, upper limb: n=2) were identified as having retrograde flow in lymph collecting vessels out of 566 confirmed lymphedema patients (lower limb: n=275, upper limb: n=291). Of the two patients with upper limb lymphedema, one had a short segment of retrograde lymph flow in the forearm. The other patient with upper limb lymphedema and one patient with lower limb lymphedema were previously diagnosed with Lymphedema-Distichiasis Syndrome. Of the remaining 18 patients with lower limb lymphedema and retrograde lymph flow, nine had initiating insect bites with lymphangitis and three had palpable benign enlarged inguinal lymph nodes evident prior to lower limb swelling onset. None had cancer-related lower limb lymphedema.

CONCLUSIONS

Retrograde lymph flow with valve incompetence in the lymph collecting vessels was a rare finding in upper limb lymphedema and a relatively uncommon in lower limb lymphedema, contradicting conventional understanding of pathological changes in lymphedema. ICG lymphography identified anticipated retrograde lymph flow in two patients with Lymphedema-Distichiasis. In the remaining patients, retrograde lymph flow may have resulted from toxic or asymptomatic lymphangitis but no association with secondary cancer-related lymphedema. These findings have implication for conservative management as well as lymphovenous anastomosis surgery where both ends of a transected lymph collecting vessel would be potential targets for anastomoses.

The effects of gravity and compression on interstitial fluid transport in the lower limb

Edema in the limbs can arise from pathologies such as elevated capillary pressures due to failure of venous valves, elevated capillary permeability from local inflammation, and insufficient fluid clearance by the lymphatic system. The most common treatments include elevation of the limb, compression wraps and manual lymphatic drainage therapy. To better understand these clinical situations, we have developed a comprehensive model of the solid and fluid mechanics of a lower limb that includes the effects of gravity. The local fluid balance in the interstitial space includes a source from the capillaries, a sink due to lymphatic clearance, and movement through the interstitial space due to both gravity and gradients in interstitial fluid pressure (IFP). From dimensional analysis and numerical solutions of the governing equations we have identified several parameter groups that determine the essential length and time scales involved. We find that gravity can have dramatic effects on the fluid balance in the limb with the possibility that a positive feedback loop can develop that facilitates chronic edema. This process involves localized tissue swelling which increases the hydraulic conductivity, thus allowing the movement of interstitial fluid vertically throughout the limb due to gravity and causing further swelling. The presence of a compression wrap can interrupt this feedback loop. We find that only by modeling the complex interplay between the solid and fluid mechanics can we adequately investigate edema development and treatment in a gravity dependent limb.

Pharmacological Treatment of Secondary Lymphedema

Lymphedema is a chronic disease that results in swelling and decreased function due to abnormal lymphatic fluid clearance and chronic inflammation. In Western countries, lymphedema most commonly develops following an iatrogenic injury to the lymphatic system during cancer treatment. It is estimated that as many as 10 million patients suffer from lymphedema in the United States alone. Current treatments for lymphedema are palliative in nature, relying on compression garments and physical therapy to decrease interstitial fluid accumulation in the affected extremity. However, recent discoveries have increased the hopes of therapeutic interventions that may promote lymphatic regeneration and function. The purpose of this review is to summarize current experimental pharmacological strategies in the treatment of lymphedema.

Liposuction in cancer-related lower extremity lymphedema: an investigative study on clinical applications

Background

Lymphedema is a progressive, noncurable condition consisting of increases in subcutaneous fat and interstitial fluid in the limbs and fibrosis during later stages. The disease most commonly affects the limbs following injury to or removal of the lymph nodes. The aim of this study was to investigate the therapeutic outcomes of liposuction for cancer-related lower extremity lymphedema.

Methods

Sixty-two patients with cancer-related lymphedema in the unilateral lower extremity were recruited for this study, and all patients underwent liposuction. The volume of hemorrhage and lipids, the operation time, and the volume changes of the affected extremity were compared by applying the t tests, and the subjective feelings of patients were compared with the chi-square tests.

Results

The total lipid volume was 2539 ± 1253.5 ml, and the hemorrhage volume was 828 ± 311.8 ml. For the comparison of objective indices, (1) the percent volume differences (PVDs) before surgery, intraoperatively, and at the 3-month follow-up were 5.5 ± 12.2 vs. 11.6 ± 18.4 vs. 43.2 ± 23.7, P < 0.05, respectively; (2) greater lipid volumes and higher liposuction rates were observed for female patients, as was a smaller volume of hemorrhage; (3) greater hemorrhage volumes were observed in patients with a history of recurrent erysipelas; and (4) greater lipid volumes and liposuction rates (LRs) and smaller hemorrhage volumes were observed for stage II than for stage III patients.

Conclusions

Liposuction is an effective therapy for cancer-related lower extremity lymphedema. Sex, stage, and recurrent erysipelas history influence the course and effect of liposuction.